File photo shows the Hainan Gibbons. Experts from over ten countries and several international organizations discuss the measures aiming to protect Hainan Gibbon during an international forum in Bo'ao, south China's Hainan Province, from March 18 to 20, 2014. Hainan Gibbon, the rarest primate and one of the most endangered mammals in the world, remains only 23 at the tropical rainforest reserve in Hainan across the world. (Xinhua/Jiang Enyu)